Friction driving device chiefly intended for cinematographic apparatus



Jan. 13, 1 931. A; Lx v. c; DEBRIE 1,789,221

FRICTION DRIVING DEVICE GHI-*EFLY INTENDED'FOR CINEMATOGRAPHIC APPARATUS Filed; Feb.- 1o, 1928 Lf WW' ZW MW mv ffy;

i hub l round which the film is wound ismounted loose on a shaft 2 to which is secured Patented Jan. v13, 1931 UNITI-:D srnras PATENT -orrica FBICTION DRIVING DEVICE CHIEFLY INTENDED FOB CINEMATOGRAPHIC APPARATUS application led February 10, 1928, Seriallo. 258,473, and in France February 23, 1927.

tial speed thereon increases. As on the other hand the feeding speed of the film remains constant, the result is that if the rotation of the hub were controlled by a rigid mechanism, the film would be driven by the hub more quickly than it would be fed by the feeding device, so that it would very soon be torn. It

`has been proposed to remove this drawback 1 by driving the film through a yielding device which yields sufficiently 'when the resistance exerted by the filmv passes beyond a certain value.

' My invention has for its object a frictional driving device of a particularly simple kind much smaller than the similar devices and requiring no powerful springs by reason of the very manner whereby the frictional stres's is exerted. A form of execution of my invention as applied to a cuematographic apparatus is shown by way of example on appended drawings wherein: g

Fig. 1 is a partly sectional side View of the device and Fig. 2 is a cross section along line A-B of Fig. l with the ball bearing omitted, vThe the inner ring 3 of a ball bearing 4 the outer ring 5 of which .rotates therefore freely round shaft 2. To the side 6 of the ring 5 are pivotally secured at 7, 7 two semi-circular brake segments 8,8normally held apart by a spring 9 disposed in the notches 10,10. provided at the free end of these segments.

These two segments are thus pressed against.

the inner flange of. a keyed to shaft 2.

-A stud 12'borne by the face 6 engages a notch provided in the lateral-wall`13 of the hub 1 and causes the latter to rotate. Thus the drum 11, driven by the shaft 2 cylindrical drum 11 rubs on the segments 8, 8 secured tothe plate 6 mounted on this shaft on the entire circumcations.

against the drum.

ference thereof. Therefore it is absolutely unnecessary to use for obtaining sufficient adherence, very owerful springs as is the case in devices of tiiis kind commonly used.

It should be well understood that numerous detail modifications can be brought to the construction of the present device Without altering the character of the invention; Thus for' instance the'ball bearing 4 might be suppressed and the ring 5 rotate directly on shaft 2. Similarly the segmentsS and 8 might bear through their innerpart on the drum 11, the action of the spring@ being in this latter case reversed. This driving device though specially studied in view of its use in cinematographic apparatuses for driving film hubs is not limited to this particular use and is adapted for the most'varied appli- What I claim is: 1. A frictional connection chiefly for cinematographic take-up mechanisms comprising va driving shaft, a reel freely mounted thereon, a part also mounted freely thereon and adapted to control the rotation of the reelz a drum keyed to the driving shaft, two semlcircular segments pivotally attached by one end to thev freely mounted part and the surface of which is in contact with the surface of the drum and a comparatively light spring connecting alone the free ends of the segments and adapted to press them against the drum.

2. A frictional connection for cinematographic take-up vmechanism comprising a driving shaft, a reel freely mounted thereon a ball bearing the inner ring of which is keyed to the shaft and the'outer ring of which is adapted to control the rotation of the reel, a drum keyed to the driving shaft, two semicircular segments pivotally attached by one end to the outer rin of the ball bearing and the surface of whic is. in contact with the surface of the drum and a comparatively light spring connectin alone the free ends of the segments and a apted to press theml In testimnywhereof I have Signed my name to this specification. p

ANDRE Lion vlcox 'cL-.nrnr Daams. 

